Kedar - son of Ishmael (Gen 25:13). The Kedarenes led a wandering predatory life in Arabia-Petraea, as the Bedouin Arabs (2Ch 21:16, 2Ch 21:17; Psa 120:5). Kedar means “blackness” (Son 1:5).
Hazor - not the city in Palestine, but a district in Arabia-Petraea. “Kingdoms” refer to the several combinations of clans, each under its own sheik.
men of the east - Kedar and Hazor were east of Judea (Jdg 6:3; Job 1:3).